1997-01-26 04:00:00 PDT SAN FRANCISCO -- I FIGURED that if I had to sleep with them I'd better find out where they come from, what they are made of and why they emit that spooky, high-pitched noise.

Turns out, most of them lie around all day in a cavernous warehouse at Pier 80. Each came to the United States by boat from Italy, then to San Francisco by rail. They're remarkably strong but sleek, complex yet easy-going. People who know them intimately - including two respected women engineers - swear they are surprisingly low-maintenance.

I'm talking about the new Muni streetcars. Those snazzy silver Bredas that cost $2 million each.

Living right on the J-line, I do not hyperbolize when I say I sleep with streetcars. They all pass by my bedroom window. The clunky, junky Boeings, the cute little restored historic trolleys and, now, the whining Bredas.

"That sound is typical with the AC propulsion system," said Mauro Melani, the chief design engineer on the Breda project. "But we will make it quieter."

Indeed, Muni is hurling new computer software, rubber sound skirts and all manner of muffler at the whine. Since Christmas, the cars' signature high-pitched wail (at once primitive and Star Trekian) has decreased so much I almost miss it. But I am in a minority. Folks along the J-line want the whine gone. So, Muni is working with the propulsion manufacturer, General Electric, on muting.

G.E. is one of several U.S. companies that helped make the Bredas. The federal government, which is picking up almost two-thirds of the tab for San Francisco's 77 Bredas, requires 60 percent of the project's sub-systems be made in America.

Three years ago, Melani left the Breda plant in Pistoia, Italy, to begin the U.S. phase of the $230 million project. Except for holiday visits home, Pier 80 - where the cars arrive in halves, are assembled and tested - is his world.

How do Muni people feel about this Father Guido Sarducci look-alike (really) telling them how to run a railroad?

"Mauro Melani is one of the finest engineers I've ever had the pleasure of meeting," said Ken Rodriguez, a 23-year Muni veteran and special assistant to the deputy director of operations.

Along with Nathan Grief, senior light rail vehicle engineer, Rodriguez has been part of the Breda project since its conception in 1989. So has one of the two women I mentioned: Elaine Cartwright, an electrical engineer and manager of the entire Breda project. Consultant Janet Gallegos, a mechanical engineer and senior associate project coordinator, climbed aboard when Breda was vying for the huge contract.

A former operator, Rodriguez says, "The love of my life is the F-line" - the restored historic trolleys that mostly travel Market Street. And yet, he pronounces the Bredas even better-built than the revered 1917 "iron monsters" that make up much of the F-line.

The Breda is "quite robust" and "very beefy," said Rodriguez. "As long as we take good care of it, do a good rehab every 30-40 years, it should last almost a lifetime."

That's a lot more than anyone could ever say for Breda's predecessor, the Boeing. Backed heavily by the feds, Muni's 128 Boeing light rail vehicles have been a pain in the asphalt since they went on line in 1980. Prone to breakdowns, especially on this city's varied terrain, they have an added disadvantage: engines that almost require the "jaws of life" to get at.

In contrast, maintenance crews can be at a Breda's guts in seconds. A repair that takes 20 minutes minimum on a Boeing (if the right fix-it people are there) takes 5 on a Breda, said Rodriquez.

"The Boeings are so unreliable; the passengers have really suffered," he said. "The operators welcome a reliable piece of equipment like this so they can concentrate on line management instead of just waiting for disaster to happen, which is how it's been."

Breda Costruzione Ferroviare is one of the top four transit car manufacturers in Europe. The Washington, D.C., metro system has 400 Bredas, Cleveland 52. Los Angeles has ordered 120. Bredas whine under Milan and Rome.

The two-segment Muni Breda is 11 feet high, 75 feet long and 9 feet wide. Its aisle is 5 inches wider than the Boeing's. There's more room inside, an extra exit door to the left of the driver and lots more glass. The windows, like the car's steel shell, are graffiti-resistant (nothing's inviolable). Vertical poles at each seat row give passengers more to hang onto at SRO rush hour.

Computers run just about everything from the temperature inside the car (72 degrees) to the raising and lowering of the exit steps. Technically, a Breda could drive itself, but even Muni would never get that silly. Besides, the operators actually have had a say in the Bredas, from the design phase right through to the current "burn-in" tests along the J-line.

So, too, some passengers. Rodriguez said that a citizen on the Muni Access Advisory Committee recently joked about one positive aspect of the Breda's haunting whine: "At least we know it's coming."